The single phase of Mn0.5Fe2.5O4 spinel crystals was prepared by the micro-emulsion method with the oil phase is DGDE (diethylene glycol diethyl ether). The characteristics of the materials have been determined by the X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX), Scanning electron microscopy (SEM) and Brunaure-Emmet-Teller (BET) nitrogen adsorption and desorption, Vibration sampling magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR). The results showed that the single phase of Fe0.5Mn0.5Fe2O4 crystalline was formed due to the substitution of Fe by Mn in the Fe3O4 crystal lattice and single phase spinel crystal is formed with the size of 6.7 nm, specific surface area ≈ 193 m2.g-1, the saturation magnetization reaches ≈ 27 emu.g-1.

In this study, cellulose nanocrystals (CNC) were chemically extracted from the waste newspapers and acetylated by reacting CNC with acetic anhydride, using sulfuric acid as a catalyst. Response Surface Methodology based on a three-factor factorial design was applied to analyze the interaction effects of reaction temperature, time, and the ratio of nanocellulose and acetic acid (wt/v) on the degree of substitution (DS) which was calculated and compared. Various experimental conditions as reaction temperature (50-70 °C), reaction time (90-150 min), and the ratio of nanocellulose and acetic acid (wt/v) (1:15-1:25) were under investigation. It was found that reaction temperature and its interaction effects have the most significant effects on DS. The acetylated CNC was characterized by FTIR and 1H-NMR spectroscopy. The highest DS (2.997) was obtained in 90 min and the CNC/acetic acid ratio of 1:15 at 70 °C.